Unit 6.7 - Energy From Biomass

Question 1

Biomass Vs Biofuel

Answer 1

• Biomass - organic matter (wood/charcoal, direid animal waste, dead leaves/brush) burned to release heat - primarily for heating homes/cooking
  - utilized primarily in developing world for heating homes and cooking food
  - easy to harvest, available, cheap/free (subsistence fuel)
  - Can also be burned in Power Plantsto generate electricity (less common than fossil fuels)
• Biofuels - liquid fuels (ethanol, biodiesel) created from biomass (corn, sugar cane, palm oil)
  - used as a replacement fuel sources for gasoline, primarily in vehicles

Question 2

Modern vs Fossil Carbon

Answer 2

• Biomass burning releases CO, Nox, PM, and VOCs - all respiratory irritants
  - 3 billion people globally cook on open, biomass burning fires, mostly in developing world
  - biomass burning indoors for heat/cooking worsens effects (pollutants trapped and concentrated)
  - worsened asthma, bronchitis, COPD, emphysema, eye irritation
• Environmental Consequences = deforestation anda ir polluants
  - lack of environmental protection laws and financial resources for other fuals lead to more biomass deforestation in developing nations
  - habitat loss, soil erosion, loss of CO2 sequestrations, air and H2O filtration
  - NOx, VOCs, and PM all contribute to smog formation

Question 3

Biofuels: Ethanol and Algae

Answer 3

• Corn and sugar cane are fermented into ethanol which is mixed with gaoline
  - Corn grain/sugar cane broken down and yeast ferment sugars -> ethanol
  - E85 or flex fuel = 51-83% ethanol + gasoline mix; used in flex-fuel vehicles
  - decreases oil consumption for transport, but is less efficient than pure gasoline
  - renewable only to the extent that the production f corn is sustainable (sugar cane is a perennial, and is more sustainable)
• Environmental consequences = a;; the negativec onsequencesof monocrop agriculture
  - soil erosion, habitat loss, GHG release (agricultural soils, trctors, fertilizers) H2O use
  - Lots of corn needed, relative to petrolum; can compete w/ human conservation of corn
  - Algae produces oils that can be used as biofuels more sustainably than corn

Question 4

Biodiesel

Answer 4

• Liquid fuels produces specifically from plant oils (soy, canola, palm)
  - palm oil biodiesel has been found to produce 98% more GHGs than FFs, due to clearing of forest for palm plantations
  - can be more ustainable if already clearled land is used, or is plantations are continually replanted (however, also causes all the environmental impacts of agriculture)